Continuity and capacity tester for testing radio receiving and transmitting sets



July 16, 1935. 1-; WENGER 2,007,992

CONTINUITY AND CAPACITY TESTER FOR TESTING RADIO RECEIVING AND TRANSMITTING sETs Filed May 26, 1932 a7" l h l i 75 w A TTOR/VE K5 Patented July 16, 1935 CONTINUITY AND CAPACITY TESTER FOR TESTING RADIQ RECEIVING MITTING SETS AND, TRANS- Floyel E. Wenger, Bluffton, Ohio, assignor to R. L.

I Triplett, Bluiiton, Ohio Application Mayv 26, 1932, Serial No.,613,669

13 Claims.

. It is the object of my invention to provide an instrument for testing the various resistances, continuities, capacities and short circuits of an audion-tube circuit of any type.

My instrument is adaptable for tests either when the operating potentials are secured from a power-pack, batteries, generators, or other electromotive sources in a circuit used for the receiving or sending of sound or sight signals, either by radio frequency waves or other means, or for any other purposes in which a vacuum or audion-tube circuit may be employed.

Referring to the drawing:

Figure 1 is a plan view of the wiring diagram.

Figure 2 is a section on the line 2-2 showing the arrangement of the switch for selecting the various terminals in the circuit for alternate test ing purposes. a Y

Referring to the drawing in detail, I represents the terminal wire in the righthand plug which is connected to a cathode, 2 indicates the filament wire, 3 the grid wire and 4 the plate wire.

The left hand plug has a cathode wire 5, filajment wiret, grid wire I and plate wire 3. The slide contact sis connected at one end through the wire It to the terminal ll of the reversing switch [2. The other terminal of this switch is connected by the wire l3 to the inner slide contact it. Bridging from the slide contact M to the terminals l5, l6, l1, l8, I9, 20, 2|, 22, 23, 24, 25, 26,21 and 28 is across over switch member 29. f This switch member is connected by an insulated bar 30 having a handle 3| to' a switch plate or finger 32 which engages the outside slide contact ring 9 and any one of the ter-'- minals, 33, 34, 35, 3t, 31, 38, 39, 40, 4|, 42, 43, 44, t and it. By moving the two switch plates 29 and 32 as so described, it is possible to selectively test the radio set and its circuits as hereinafter described. Y The line 4'! is connected by the clip 48 to B- of the B supply, forming the ground or common terminal. The CG clip is used to connect the control grid of tubes having the grid terminal of such shape to receive the clip, or to plates of a variable condenser, or any other desired connection. e H

The terminals 59 and 5!] are connected to an alternating current source. The cycles and voltage of the source should correspond to the calibrations of the microfarad meter 5i which-is connected by the wire 52 to the line 53'which terminates in the adjustable finger 54 engaging the resistance 55 which is connected by the wire 56 i to the terminaliv il The. other side of the meter is connected by the line 5'! to the. terminal 58. This terminal is connected by the wire 59 through the resistance 6i! to switch arm El which may engagethe terminal 62 or the terminaltS on the wire 53. The terminal 58 is connected by 5 the wire 64 to the terminal 65 which is one terminal of the double pole, double throw switch l2, the other corresponding switch terminal 66 connects the wire 6'! which terminates, in the terminal 49.1 The wire 6 4 may be directly connected to the wire 61 by the push button 68.

The third phase of this invention comprises the following circuit and apparatus: A voltage ohm meter 69 which is connected on one side by the wire it? to the double pole, double throw switch terminal at H. The other terminal is designated Hand is connected to the wire 13. .The wires 13 and lil may be connected together by the push button switch 14. The other end of the wire 13 is connected to a battery 15 which is tapped at intervals to resistances 16, ll, 18, i9 and Bi). The free ends of the resistances are engaged by the switch arm 8! engaging with the terminals 82, 83, 8d, 85, 86 and 81 respectively. The switch arm itself is connected by the wire 88 to an adjustable finger contact 89 engaging the resistance 90 which in turn is connected to the other terminal of the ohm meter 69.

It will be understood that the ohm meter 69 is so adjusted to correspond with the battery 15 orother similar electro motive source.

Operation This instrument is capable of a large variety of tests, the principal ones of which are hereinafter described.

When it is desired to test the continuityof a power circuit of the set, which means there is a test to be made from the power circuit to the voltage distribution net of the set circuit, the tubes from the set to be tested are removed and 'the left hand plug comprising the wires 5,6, l and 8 is placed in the rectifier socket, which has been formerly occupied by the rectifier tube. successively plug the right hand plug comprising the wires l, 2, 3 and 4 in each one of the rernaining tube socketsof the set in order to make any one of the following tests. These tests are made by successively moving the switch plates 29 and 32 from the positions indicated at A, B, C, D, E, F, G, H, I and J. For instance, in position A the contact finger 29 bridges the slide ring l4 and terminal l5 at the sametime that contact member 32 bridges the slide ring 9 and the terminal 33. In position B the contact plate and 29 bridges the slide ring Hi to terminal is and the contact plate 32 bridges the slide ring 9 to the terminal 34. In position C the terminals l1 and 35 are engaged. In position D the terminals l8 and 33 are engaged. In position E the terminals l9 and 37 are engaged. In position F the terminals and 38 are engaged. In position G the terminals 2i and 39 are engaged. In position H the terminals 22 and 35 are engaged. In position I the terminals 23 and ii are engaged. In position J the terminals 24 and 12 are engaged. In position K the terminals 25 and 43 are engaged. In position L the terminals 26 and 44 are engaged. In position M the terminals 2'! and G5 are engaged. In position N the terminals 23 and 46 are engaged.

The following are the tests for each of these positions A to J when the left hand plug is in the left hand rectifier socket and the right hand plug is successively moving from socket to socket towards the rectifier socket in the set. Such tests are:

Position A.-Test the circuit condition and for .defects between the usual heater contact and B.

Position B.Test the circuit condition and for defects in either the resistor or condenser from the usual cathode contact to B-.

Position C.Test the circuit condition and for defects in either the resistor or condenser from the usual grid contact to B- Position D.--Tcst the circuit condition including the resistor and condenser between the usual plate contact and B.

Position E.Test for defective secondary tube coupling from the usual control grid to 3-.

Position F.Test for defects in one-half of the high voltage secondary winding of the power transformer from the rectifier plate contact to B.

Position G.Test for defects in the other half of the high voltage secondary winding of the power transformer, such as short circuits or open windings.

Position H.I est for defects in the circuit from the filament contact of the rectifier tube to the plate contact of the amplifying or 6.6-. tector plate. Defects can be either short circuits or open windings.

Position I.'I'est for defects from the high D. C. voltage side of the rectifying tube to the usual grid prong of the amplifying or detector tube.

Position J.Test-for defects from the high D. C. voltage of the rectifying tube to the usual cathode contact of the amplifying or detector tube.

When it is desired to test the degree of continuity between'the same elements of difierent tube sockets, the right hand plug comprising the wires l, 2, 3 and 4 is inserted in the radio frequency socket-of the set and the left hand plug is inserted in the second adjacent socket. The left hand plug of the testing instrument comprises the wires 5, 6, 1 and 8. In' other'words, by placing the right hand plug in one amplifier socket, for instance, and placing the left hand plug in the next adjacent amplifier socket, the test is made for the degree of continuitybetween thesame elements in the difierent sockets.

For this purpose set the switch plates 29 and 32*at position K and make the following tests at the successive positions K, L, M and N;

Position K.Test for defects between the two plate contacts.

Position L.Test for defects between the usual grid contacts.

Position M .-Test for defects between the usual cathode contacts.

Position N.-Test for defects between the usual heater contacts.

The defects so sought will be either a short circuit, open connection of wiring which should be repaired.

My invention is also capable of testing for open filter chokes, high resistance filter chokes, open speaker coils where they are used as filter coils, high resistance filter chokes, field coils when usedas chokes, loose joints, high resistance joints, improper soldering, resistance of the voltage divider, the various resistances of the voltage divider, etc. test the windings of the tube coupling transformers; measure the resist ance of the resistance coupling circuits and measuring resistance of the transformer coupling circuits; measure the degree of continuity of onehalf of the secondary of the power transformer to the usual tap of the power transformer, which is usually B-battery; measure the other half of that same high voltage secondary winding of the power-transformer to its usual center tap.

By my invention is obtained a more accurate measure of the condition of the high voltage secondary than from a voltage measurement. It will measure the degree or" the continuity from the plate Contact of an audiontubeto the heater contact or" a rectifier tubethe heater contact of the rectifier tube usually furnishing very high D. C. potential.

The ohm meter also measures the degree of continuity from the usual cathode contact to the heater connection ofthe-rectifier tube which is the high voltage connection.

By having the clip 58 connected to either B-battery or if B- returns to chassis, the resistance or the capacity is measured from the usual heater circuit to either B or the chassis.

-Ohm meter readings are also made covering the value of the cathode grid biasing resistor, the value-ofthe cathode biasing resistor condenser, and resistance values of the entire voltage divider or any portion of the voltage divider terminating at a socket contact.

The test includes the entire secondary circuit for degree of continuity. I It will measure the degree of continuity from the usual plate contact of one tube circuit to the usual plate contact of any other tube within the circuit. 7

It will measure the degree of continuity from the usual grid contact .of one tube to any other grid contact in the circuit.

This instrument can also be used for testing the capacity 01f the condensers connected in the radio circuit.

' In order to measure the capacity of the condenser I follow the following procedure:

I first close the button '68 and'ad-J'ust resistance 55 until the needle on the microfarad meter registe'rs maximum. I then lift the 'button'68 and close the switch 12 on-the terminals 85 and65 adjacent the button 68 and thereby test the capacity of the condensers. It will be understood that A-C lines are connected to a suitable source of AC current both as to-cycles and voltage to match the meter.

Thereafter, upon the closing of switch, I move my switch plates 25! and-32 on the collector rings todifierent positions in order to measure ti ie diiierent capacities in the circuit.

It-wilibe understood that the finger-6| will be moved from low to high position, or vice versa, according to the capacity of the condenser under test in the set sothat the proper reading'of the metertl maybe secured. r

rent according to the resistor employed in the radio set so that the resistance selected will correspondv to the resistor of the set andwhen the resistor in the set is tested the needle on the ohm meter when at maximum according to the resistances it to 8d as set can return in the reverse direction when testing value of the resistor in the set.

The purpose of this is to limit the amount of current that the resistor will register when tested on the scale or the instrument used.

It will be further observed that, when the switch I2 is closed on terminals H and I2 and the switch iii is in off position engaging the contact member s2. then the rotating 'oi the switch meter 5 l plates 29 and 32 on the slide wire selector switch will bring about different voltage readings between the diiierent set connections on the ohm meter which will be used as a volt meter.

On the other hand, if the switch 52 engages the terminals 65 and 66 the same procedure can be employed for reading voltages on the microfarad In this test the alternating current supply lines 56 and iii would not be connected to the tester but the current would be taken from the set socket where the different voltages under test apply. This test is when the set is connected toits regular supply and is operated.

It will be understood that I desire to comprehend within my invention such-modifications as may be necessary to adapt it to varying conditions and uses.

Having thus fully described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. In a tester, in combination, a plug having cathode, filament, grid and plate connections,

each of which terminate in a plurality of contact members, asecond plug having similar connections terminating in a plurality of contact members, said contact members being arranged in pairs, one from each plurality of contact members, selector switch slide rings adapted to be connected to a source of current through an indicating instrument, and switch plates adapted to connect said slide rings to pairs of said terminals.

2. In a tester, in combination, a plug having cathode, filament, grid and plate connections, each of which terminate in a plurality of contact members, a second plug having similar connections terminating in a plurality of contact members, said contact members being arranged in pairs, one from each plurality of contact members, selector switch slide rings adapted to be connected to a source of current through an in dicating instrument, switch plates adapted to connect said slide rings to pairs of said terminals,

other terminals connected to a source of potential. 3. In a tester, in combination, a plug having cathode, filament, grid and plate connections, each of which terminate in a plurality of contact members, asecond plug having similar connections terminating. in a plurality of contact members, said contact members beingarranged in pairs, one from each plurality of contact members,

selectorv switch slide rings adapted to be connected to a source of current through an indicating instrument, switch plates adapted to connect said slide rings to'pairs of said terminals, other terminals connected to a source of potential, such as the B. side of 'a B-battery.

4. In a radio testing set, a plug having cathode,

filament, grid and plate terminals; a second plug having similar terminals, aplurality of contact membersconnected to said respective terminals,

.slide'wires associated with said terminals having 1 free ends thereof connected to a two-pole switch, and a m'icrofarad testing circuit con- :nected thereto by said switch, and means of supplying said microfarad testing circuit with a source of alternating current.

5. In a radio testing set, a plug having cathode,

filament, grid and plate terminals, a second plug having similar terminals, a plurality of contact members connected to said respective terminals, slide wires associated with said terminals having free ends thereof connected to a twopole switch, and a microfarad testing circuit connected thereto by said switch, and means of supplying said microiarad testing circuit with a source of alternating current, and a second switch adapted to complete said microfarad circuit when the slide wire switch is out of contact therewith.

6. In combination in a testing set, a plurality of plug circuits terminating in spaced terminals and connected to a pair of plugs, common slide wires associated with said terminals, switch means for connecting said slide wires to said terminals in pairs, said pairs including terminals of the same plug and terminals of different plugs, and a slide wire circuit adapted to be connected to a source of current through an indicating instrument.

7. In a tester, in combination, a set of plug circuits comprising cathode, filament, grid and plate terminals, a second set of plug circuits having similar terminals, a pair of slide wires adapted to be connected to a source of current through an indicating instrument, slide wire selector switches adapted to connect terminals of one set to the terminals of the other set.

8. In a tester, in combination, a testing circuit comprising a slide wire circuit and a plurality of plug circuits, a second circuit having a source of alternating current supply, a microfarad meter across said second circuit, and adjustable resistances in said second circuit, a switch adapted to open and close said second circuit and a seond switch adapted to connect said circuits.

9. In a tester, in combination, a testing circuit comprising a slide wire circuit and a plurality of plug circuits, a second circuit having a source of alternating current supply, a microfarad meter across said second circuit, adjustable resistances in said second circuit, a switch adapted to open and close said second circuit, a switch in parallel with the meter, and switch means for connecting said second circuit into the slide wire circuit.

10. In a testing instrument, a testing circuit comprising a slide wire circuit and a plurality of plug circuits, a source of potential such as a battery, a plurality of resistance members tapped in at intervals in said battery, a selector switch for engaging said resistance members selectively, an ohm meter circuit connected to said switch, means to connect the ohm meter circuit to the testing circuit, an adjustable resistance therein, an ohm meter therein, and means of closing said ohmcmeter circuit.

11. In a testing instrument, =a-testing circuit comprising a slide wireflcircuit and "a plurality of plug circuits, a source of potential such .aswa battery, a plurality of resistance members tapped in at intervals in said battery, ia"selectorswitch for engaging said resistance members selectively, an ohm meter circuit connected to saidswitch, means to connect the ohm mneter-circuit-to the testing circuit an adjustable resistance therein, an ohm meter therein, means of closing said ohm metercircuit, and-means of opening said ohm meterci-rcuit independently of the closing means.

12. In combinatiom'in a radio testing set,-a slide wire circuit, aplurality of plug circuits, La selector switch for connecting the plug circuits into the slide wire circuit, a battery, a plurality emzcez of resistances tapped {at intervals into said battery, an-ohm meter adapted to be selectively connected on one side to the resistances :and connected on its other side to the battery, said battery, "ohm meter, resistances I and connections forming acircuit, and means to connect the lastnamed'circuit to the slide wire circuit.

1'3. In combination, in-a radio testing set, a slide" wire circuit, a plurality of plug circuits, a

selector-switch for connecting 'the'plug circuits into the slide wire circuit, a meter circuit, and means to connect-the meter -circuit into the slide 'wire circuit said meter circuit, a battery, a meter connected on'one side to one side of the battery ianda connection from the other side of the meter tothe battery comprising a plurality of resistance members tapped into the battery at intervals-and a switch for engaging said resistance members selectively.

FLOYD E. WENGER. 

